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Updated: Jul 17, 2026
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Construction and Application of Cerebral Functional Region-Based Cerebral Blood Flow Atlas Using Magnetic Resonance Imaging-Arterial Spin Labeling
Published on: May 31, 2024
Intravascular effect in velocity-selective arterial spin labeling.
Summary
Velocity-selective arterial spin labeling (VS-ASL) improves magnetic resonance imaging (MRI) perfusion measurements. This study optimized VS-ASL, eliminating the need for cerebrospinal fluid suppression in human brain perfusion imaging.
Area of Science:
- Medical Imaging
- Biophysics
Background:
- Arterial spin labeling (ASL) is a key MRI technique for assessing tissue perfusion.
- Conventional ASL methods face errors due to T1 relaxation during inflow time.
- Velocity-selective ASL (VS-ASL) offers an alternative by tagging based on blood flow velocity.
Purpose of the Study:
- To optimize VS-ASL for improved accuracy in perfusion measurements.
- To investigate the impact of cutoff velocity (Vc) on VS-ASL signal and inflow time (TI).
- To eliminate the requirement for cerebrospinal fluid (CSF) suppression in VS-ASL.
Main Methods:
- Utilized a 90-180-90 radiofrequency pulse train with flow-sensitive gradients for VS-ASL.
- Modified diffusion gradients within the VS pulse train (lower amplitude, longer separation).
- Reduced the b-value to minimize artifacts and eliminate CSF suppression needs.
Main Results:
- Optimized VS-ASL allows for accurate perfusion measurements with reduced inflow time dependence.
- Higher cutoff velocities (Vc) result in maximal signal at shorter TI due to intravascular signals.
- The modified VS pulse train successfully eliminated the need for CSF suppression for Vc down to 2 cm/s.
Conclusions:
- VS-ASL is a viable technique for precise local tissue perfusion measurement using MRI.
- Optimized VS-ASL parameters enhance accuracy by mitigating T1 relaxation and intravascular signal issues.
- This advancement simplifies VS-ASL protocols for human brain perfusion imaging.
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